structuredAttrs is enabled

trying https://github.com/modelcontextprotocol/python-sdk/archive/refs/tags/v2.2.0.tar.gz
  % Total    % Received % Xferd  Average Speed  Time    Time    Time   Current
                                 Dload  Upload  Total   Spent   Left   Speed

  0      0   0      0   0      0      0      0                              0
  0      0   0      0   0      0      0      0                              0
  0      0   0      0   0      0      0      0                              0

  0      0   0      0   0      0      0      0                              0
100  3.94M   0  3.94M   0      0  3.70M      0           00:01              0
100  3.94M   0  3.94M   0      0  3.70M      0           00:01              0
100  3.94M   0  3.94M   0      0  3.70M      0           00:01              0
unpacking source archive /nix/var/nix/builds/nix-1831896-1462251230/download.tar.gz